The present invention relates to an apparatus for polishing the spherical surface of an optical lens or the like.
In recent years, optical technique have been utilized more and more in various industrial fields. Consequently, there is a growing demand for optical lenses and, hence, the development of a lens polishing apparatus having high productivity. According to a first conventional method (recess method) for polishing a lens, a plurality of workpieces are adhered to a workpiece holder opposed to one grindstone. According to a second conventional method disclosed in Japanese Laid-Open Patent Publications No. 61-173852 and No. 3-19740, one workpiece is polished by one grindstone.
In the first conventional method, the workpiece is adhered to the workpiece holder. Therefore, it is difficult to operate the apparatus with automation. In the second conventional method, while a polished workpiece is being replaced with an unpolished workpiece, the polishing operation is suspended. Thus, the apparatus has low productivity. In order to polish the lens with high precision, it is necessary to replace the workpiece holder periodically, because the workpiece holder deteriorates in a short period of time. But it takes long for an operator to replace the workpiece holders, because the workpiece holder to be removed from the apparatus is screw-fixed. During the replacing operation, the polishing operation has to be suspended.